1. Field of the Invention
The present invention relates to an electronic blur correction device and an electronic blur correction method capable of effectively compensating for an image blur caused by hand shakes and the like. Particularly, the present invention relates to an electronic blur correction device and an electronic blur correction method for compensating for mutual blurring of a plurality of images continuously shot at a blur tolerable exposure time and combining the images for which a blur is corrected.
2. Description of the Related Art
It is conventionally known that a blur may occur in a shot image due to the influence of photographer's hand movements upon shooting a still image with an imaging apparatus. Therefore, various measures have been taken to prevent this blur problem. For example, Japanese Patent Application Laid-Open No. 2001-86398 discloses an imaging apparatus, which compensates for mutual blurring of a plurality of images obtained during continuous a shooting performed plural times for a short exposure time in which blur is acceptable, and adds the plurality of images to generate a combined image for which a blur is corrected.
It usually takes several tens to hundreds of milliseconds to read an image from an image pickup device. Further, when the focal length of a photographing lens of a 35 mm film camera is f [mm], a blur tolerable exposure time is often set to 1/f [sec] from an empirical perspective. Therefore, if shooting is performed with a photographing lens having, for example, focal length f=100 [mm], the blur tolerable exposure time t is t= 1/100 [sec]=10 [msec]. In the blur correction technique as described in Japanese Patent Application Laid-Open No. 2001-86398, if the cycle of reading an image from the image pickup device of the camera is, for example, 100 [msec], exposure is performed intermittently every time period (10 [msec]) equivalent to 1/10 of the reading cycle. Then, a plurality of read, time-division images are compensated for mutual blurring and combined together.
In this case, the time interval from the end of one time-division image exposure to the start of the next time-division image exposure cannot be set shorter that the image reading cycle. Therefore, in the above example, the next time-division image exposure is started after a lapse of 90 [msec] since completion of the previous exposure of 10 [msec].